RU2783741C1 - Wedgeless parallel gate valve for locking devices - Google Patents

Abstract

FIELD: pipeline valves.

SUBSTANCE: invention relates to pipeline valves and can be used in water and steam pipelines of thermal and nuclear power plants, as well as chemical and oil and gas enterprises. A wedgeless parallel type gate consists of a platform, an eye with a thrust bearing, two sealing discs assembled with spherical hinges having one center of rotation, sliders, spacers and a spring. In the intermediate “open” position, the valve moves along the guide in the direction of the lower stop, the disks are pressed against the platform by a spring by means of sliders, and there are guaranteed gaps between the sealing disks and the sealing surfaces of the valve body, which exclude contact between the surfaces during movement. At the moment the valve stops when the platform rests against the stop, the flow area of ​​the pipeline is minimal and is determined by the size of the gaps, the disks are still pressed against the platform by a spring through the sliders, the position of the valve corresponds to the beginning of the movement of the disks in the direction perpendicular to the guide, and the spindle up to the “closed” position beyond crawler count. In the "closed" position, the disks are pressed against the sealing surfaces of the housing due to the converted axial force on the spindle through the sliders.

EFFECT: invention is aimed at increasing the reliability and service life of valves.

5 cl, 4 dwg

Description

The invention relates to pipeline shut-off valves, in particular to the device of valves, and can be used in pipelines for water and steam of thermal and nuclear power plants, as well as chemical and oil and gas enterprises. Wedgeless valve of parallel type, which uses a sliding mechanism, allows you to convert the longitudinal movement of the control spindle into a rectilinear movement of the sealing discs of the valve, coaxial to the sealing surfaces of the valve body when it is closing and opening. EFFECT: invention makes it possible to increase the service life of shut-off valves by changing the trajectory of movement of the sealing disks of the gate, which makes it possible to exclude the presence of sliding friction between the sealing surfaces of the gate and the housing.

Known designs of valves (gate valves) using gates wedge and parallel types. A parallel valve is used in the main gate valve D _at 850 nuclear power plants with a VVER-1000 reactor. Wedge-shaped valves are used in shutoff valves on water and steam pipelines of NPP circuits with RBMK and VVER reactors [1].

Known valve according to patent RU 2193129 C1, which relates to the field of valves and is intended for use in locking devices installed on pipelines transporting liquid and gaseous media. The gate valve contains a body with seats and two shut-off discs. The discs are made with wings. The valve is made with guides. The latter ensure the movement of the discs between the sealing surfaces of the seats. A spacer wedge is placed between the disks. It is made separately from the spindle and ensures that, when the valve is closed, the disks are pressed against the seats for sealing and they are removed from the seats at the beginning of the valve opening. The guides are made in the body. Top and bottom windows of various heights are made in the guides. The wings are made with bevels and are located on the disks with the possibility of their entry into the windows to provide pressing and retraction of the disks, respectively. EFFECT: invention allows to simplify the valve design.

The main disadvantage of the known technical solutions of the aforementioned valves, which limits their service life, is the presence of sliding friction between the sealing surfaces at the moment of closing and opening, which can lead to scoring of the sealing surfaces. An additional factor limiting the service life of valves in the presence of sliding friction is increased wear of the sealing surfaces in the presence of abrasive particles (sludge) in the working medium. The currently used expensive technology for applying hardbanding to the sealing surfaces with their subsequent high-precision machining partially solves the problem of wear, but does not eliminate it.

The objective of the invention is to eliminate the main drawback of existing gates - the presence of sliding friction of the sealing surfaces, and thereby increase the service life of valves between technical scheduled maintenance.

The technical result of the proposed solution is to increase the reliability and service life of valves.

1. The technical result is achieved due to the fact that the wedgeless gate of parallel type consists of a platform, an earring with a thrust bearing, two sealing discs assembled with spherical hinges having one center of rotation, sliders, spacers and a spring, characterized in that in the intermediate position " ajar” movement of the shutter is provided along the guide in the direction of the lower stop, the discs are pressed against the platform by a spring by means of sliders, and there are guaranteed gaps between the sealing discs and the sealing surfaces of the valve body, excluding contact between the surfaces during movement, at the moment the shutter stops when the platform rests against the stop, the flow area of the pipeline is minimal and is determined by the size of the gaps, the disks are still pressed against the platform by a spring through the sliders, the shutter position corresponds to the beginning of the movement of the disks in the direction perpendicular to the guide and the spindle up to the “closed” position due to the sliders, in the “closed” position dug" disks are pressed against the sealing surfaces of the body due to the converted axial force on the spindle through the sliders.

A feature of the proposed valve is the movement of the sealing discs relative to the sealing surfaces of the body (saddle), eliminating sliding friction of the sealing surfaces relative to each other in all modes of operation of the valves.

In FIG. 1 shows the proposed design of the shutter. The shutter consists of the following main parts: platform 1, lugs with a thrust bearing 2, sealing discs 3 complete with spherical joints and spacers, a roller with retaining rings 4, a spring 5 and sliders 6.

The principle of operation of the proposed shutter, as part of the shut-off valves, is explained sequentially in Fig. 2, fig. 3 and FIG. four.

In FIG. 2, the proposed shutter is shown at the moment of its movement, coinciding with the direction of movement of the control spindle 10, in the intermediate position "ajar". The valve moves along the guide 9 in the direction of the lower stop 8. The discs 3 are pressed against the platform 1 by the spring 5 by means of the sliders 6. There are guaranteed gaps A between the sealing discs 3 and the sealing surfaces 7 of the valve body, excluding contact between the surfaces during movement.

In FIG. 3, the proposed shutter is shown at the moment of its stop when the platform 1 rests against the stop 8. The position is “on the stop”. The flow area of the pipeline is minimal and is determined by the size of the gaps A. The discs 3 are still pressed against the platform 1 by the spring 5 through the sliders 6. There are still guaranteed gaps A between the sealing discs 3 and the sealing surfaces 7 of the valve body, excluding contact between the surfaces. The position of the shutter corresponds to the beginning of the movement of the disks in the direction perpendicular to the guide 9 and the spindle 10 up to the “closed” position (see Fig. 4) due to the sliders 6.

In FIG. 4 the proposed shutter is shown in the "closed" position. The flow section of the pipeline is blocked. The disks 3 are pressed against the sealing surfaces of the housing (saddle) 7 due to the converted axial force on the spindle 10 through the sliders 6.

To increase the strength and reduce the weight of the product, the sealing discs can have fragments of a spherical shape.

The ends of the platform, to which the disks assembled with spherical hinges and spacers are pressed under the action of a spring, can have spherical surfaces formed with a radius equal to the outer radius of the disk, which ensures the presence of gaps between the disks and the sealing surfaces of the valve body.

The spherical surfaces of the discs and sliders provide self-adjustment of the discs when they touch the sealing surfaces of the valve body.

To ensure sealing between the discs and the sealing surfaces of the valve body, the contact is made along the line "torus on the plane" (higher mechanical pair).

Sources of information:

one . Power fittings for nuclear power plants and thermal power plants, Research Institute of Economics in power engineering, 1986

Claims (5)

1. Wedge-free valve of parallel type, consisting of a platform, an earring with a thrust bearing, two sealing discs assembled with spherical hinges having one center of rotation, sliders, spacers and a spring, characterized in that in the intermediate position "slightly open" the movement of the valve is provided along the guide in the direction of the lower stop, the discs are pressed against the platform by a spring by means of sliders, and between the sealing discs and the sealing surfaces of the valve body there are guaranteed gaps that exclude contact between the surfaces during movement, at the moment the gate stops when the platform rests against the stop, the flow area of the pipeline is minimal and is determined by the size of the gaps , the disks are still pressed against the platform by a spring through the sliders, the shutter position corresponds to the beginning of the movement of the disks in the direction perpendicular to the guide, and the spindle up to the “closed” position due to the sliders, in the “closed” position the disks are pressed against the sealing surfaces body due to the converted axial force on the spindle through the sliders. 2. Wedgeless shutter according to claim 1, characterized in that the sealing discs have fragments of a spherical shape. 3. A wedgeless gate according to claim 1, characterized in that the ends of the platform, to which the disks assembled with spherical hinges and spacers are pressed under the action of a spring, have spherical surfaces formed by a radius equal to the outer radius of the disk. 4. A wedgeless gate according to claim 1, characterized in that the spherical surfaces of the disks and sliders provide self-adjustment of the disks when they touch the sealing surfaces of the valve body. 5. A wedgeless gate according to claim 1, characterized in that the contact between the discs and the sealing surfaces of the valve body is made along the line "torus along the plane".

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